JP2022006913A - Floor slab replacing method - Google Patents

Abstract

To provide a floor slab replacement method capable of opening traffic without carrying out reinforcement work even in the middle of the floor slab replacement work of an existing composite girder and minimizing a traffic blocking period.SOLUTION: In a floor slab replacing method for removing an existing floor slab 3a of an existing composite girder and sequentially replacing it with a new floor slab 3b, a temporary floor slab 5 having strength capable of being regarded as a rigid body against a force acting in a bridge axis direction is installed at a removal place of the existing floor slab 3a at least on a main girder 2, and an axial force is transmitted to the existing floor slab 3a before removal and the new floor slab 3b via the temporary floor slab 5 on the main girder 2.SELECTED DRAWING: Figure 4

Description

The present invention relates to a floor slab replacement method for replacing an existing floor slab of a synthetic girder with a new floor slab.

In the floor slab replacement work for existing synthetic girders, it is required to minimize the traffic cutoff period. Conventionally, traffic is blocked in the middle of the night when traffic is light, a certain section of the existing deck is removed, a new deck is placed in that section, and traffic is opened after curing (for example, Patent Document 1). reference).

Japanese Unexamined Patent Publication No. 2005-282272

However, it may not be possible to arrange and cure the new floor slab within the required traffic cutoff period. In this case, it is necessary to install a lining board etc. at the removed part of the existing floor slab to open the traffic, but when the existing floor slab is removed, it is temporarily a non-synthetic girder.
It was necessary to attach angle lumber bolts to the web (near the flange) and to reinforce the main girders by connecting them horizontally with H-shaped steel. Since the reinforcement work is performed before the removal of the existing floor slab, there is a problem that it is extremely difficult to load and install the reinforcement member in a narrow space under the girder.

The present invention provides a floor slab replacement method capable of opening traffic without performing reinforcement work and minimizing a traffic cutoff period even during the floor slab replacement work of an existing synthetic girder. It is in.

The floor slab replacement method of the present invention is a floor slab replacement method in which the existing floor slab of the synthetic girder is removed and replaced with a new floor slab in sequence, and the force acting in the bridge axis direction is applied at least on the main girder. A temporary deck having a strength that can be regarded as a rigid body is installed at the removal location of the existing deck, and on the main girder, the temporary deck before removal and the new deck are combined with the temporary deck. It is characterized in that the axial force is transmitted through the.
Further, in the floor slab replacement method of the present invention, between the new floor slab and the temporary floor slab, a slit formed and a joint reinforcing bar protruding from the new floor slab on the main girder are fitted. Axial force may be transmitted by using a plurality of bearing plates supported by the combination and jacks arranged opposite to each other between the bearing plate and the temporary deck.
Further, in the floor slab replacement method of the present invention, the jack has a plate-shaped jack body and a plate-shaped jack body.
A rod projecting from one side of the jack body and a handle provided on the side surface of the jack body are provided, and the jack body is tilted from above by the handle so that the projecting direction of the rod coincides with the bridge axis direction. In the supported state, the rod may be projected to transmit an axial force between the new floor slab and the temporary floor slab.

According to the present invention, even during the floor slab replacement work of the existing synthetic girder, the temporary floor slab can function as a strut installed on the main girder to secure sufficient rigidity, so that sufficient rigidity can be secured without performing reinforcement work. It has the effect of opening traffic and minimizing the period of traffic interruption.

It is a figure which shows the structure of the existing synthetic girder which is the object of the floor slab replacement method which concerns on this invention. It is a figure which shows the structural example of the temporary floor slab installed in the place where the existing floor slab shown in FIG. 1 was removed. It is a top view which shows the installation example of the temporary floor slab shown in FIG. It is a figure which shows the example of the axial force transmission to the temporary floor slab shown in FIG. It is a figure which shows the installation example of the bearing plate shown in FIG. It is a figure which shows the structural example of the jack shown in FIG.

Next, an embodiment for carrying out the present invention (hereinafter, simply referred to as “embodiment”) will be specifically described with reference to the drawings.

With reference to FIG. 1, the existing synthetic girder 1 is configured by rigidly joining a floor slab 3 made of reinforced concrete or the like to the upper surface of a main girder 2 made of H-shaped steel or the like erected between piers.

In the floor slab replacement work, as shown in FIG. 1 (a), after a certain section of the existing floor slab 3 is sequentially removed in the replacement direction, a new floor slab 3 is installed on the floor slab on the base point side of the adjacent replacement. It is fixed to 3 and the main girder 2. Hereinafter, the existing floor slab 3 will be referred to as an existing floor slab 3a, and the new floor slab 3 will be referred to as a new floor slab 3b. Note that FIG. 1A shows a state in which the two existing floor slabs 3a have been removed.

As shown in FIG. 1A, the rigidity of the composite girder 1 decreases when a certain section of the existing floor slab 3a is removed. However, as shown in FIG. 1 (b), a strut such as H-shaped steel is placed between the new floor slab 3b and the existing floor slab 3a on the upper flange 2a of the main girder 2 where the existing floor slab 3a is removed. It was found by simulation that sufficient rigidity can be secured by installing 4 as a tension rod. The strut 4 is an axial force transmission member that transmits an axial force between the new floor slab 3b and the existing floor slab 3a, and the axial force transmission member is on the upper flange 2a of the main girder 2, so that the main girder 2 The compressive force (stress degree) can be relaxed, and sufficient rigidity can be secured without the need for reinforcement. In the simulation, a 200 mm × 200 mm H-shaped steel was installed as a strut 4.

Therefore, in the floor slab replacement method of the present embodiment, the temporary floor slab 5 shown in FIG. 2 is installed at a place where the existing floor slab 3a is removed as shown in FIG. 3, and is made to function as a strut 4. It enables traffic to be opened even during the floor slab replacement work for synthetic girder 1. The temporary floor slab 5 is a plate-shaped member having substantially the same size as the new floor slab 3b, and in the floor slab replacement method of the present embodiment, the same number of temporary floor slabs 5 as the removed existing floor slab 3a are installed. ..

With reference to FIG. 2, the temporary floor slab 5 includes a lining plate 51 and an asphalt pavement 52 provided on the lining plate 51, and a steel balustrade 53 is used as a substitute for the wall balustrade of the new floor slab 3b. It is provided. Further, at a position located on the upper flange 2a of the main girder 2 when the lining plate 51 is installed, a bearing surface 54 perpendicular to the bridge axis direction is formed by a steel plate or the like. The bearing surfaces 54 are provided on both end surfaces in the bridge axis direction.

The lining plate 51 is, for example, an H-shaped steel material and a steel plate integrated by welding, and can be regarded as a rigid body with respect to a force acting in the bridge axis direction at least on the upper flange 2a of the main girder 2. It has the strength to be able to. A precast plate may be used as the lining plate 51.

It should be noted that the gibber provided on the upper flange 2a of the main girder 2 at a predetermined pitch is penetrated into the gibber hole formed on the lower surface of the new floor slab 3b, and a filler such as mortar is placed in the gibber hole. Then, the main girder 2 and the new floor slab 3b are fixed. Therefore, depending on the progress of the floor slab replacement work, a gibber is provided on the upper flange 2a of the main girder 2. Therefore, it is preferable that the shape of the lower surface of the lining plate 51 does not interfere with the gibber provided on the upper flange 2a of the main girder 2. In this case, the temporary floor slab 5 can be used to open the traffic regardless of the progress of the floor slab replacement work.

As shown in FIG. 4A, the gap between the installed temporary floor slab 5 and the new floor slab 3b transmits axial force using a plurality of bearing plates 6 and jacks 7.

The bearing plate 6 is made of a steel plate or an iron plate, and as shown in FIG. 5, a slit 61 into which a joint reinforcing bar 31 protruding at equal intervals is formed at the end of the new deck 3b in the bridge axial direction. ing. The slits 61 are formed at two locations on the same side at intervals where the joint reinforcing bars 31 are projected, and the two protruding joint reinforcing bars 31 are fitted with the two slits 61 from above. The bearing plate 6 is configured to be supportable by two joint reinforcing bars 31.

With reference to FIG. 6, the jack 7 has a plate-shaped jack main body 71 having substantially the same area as the bearing plate 6, a plurality of rods 72 protruding from one surface side of the jack main body 71, and a plurality of protruding rods 72. It is provided with a handle 73 that can support the jack body 71 from above so that the direction coincides with the bridge axis direction. The plurality of rods 72 are evenly arranged at positions avoiding the two slits 61 in a state where the jack main body 71 and the bearing plate 6 face each other.

In the transmission of the axial force using the plurality of bearing plates 6 and the jack 7, first, the total thickness is increased by the two joint reinforcing bars 31 protruding from the new floor slab 3b on the upper flange 2a of the main girder 2. A plurality of bearing plates 6 having a flange equal to or greater than the value obtained by subtracting the maximum protrusion length of the rod 72 from the protrusion length of the joint reinforcing bar 3 are supported. Then, using the handle 73, the jacks 7 are arranged to face each other between the plurality of bearing plates 6 and the bearing surfaces 54 of the temporary deck 5, and the plurality of rods 72 are projected by hydraulic pressure or the like. As a result, pressing force is applied to the temporary floor slab 5 and the new floor slab 3b in directions away from each other, and a bridge is applied to the temporary floor slab 5 and the new floor slab 3b on the upper flange 2a of the main girder 2. Axial force in the axial direction is applied.

It is preferable to arrange the jacks 7 so as to face each other so that the protruding direction of the rod 72 is on the bearing plate 6 side (new floor slab 3b side). In this case, even if the total thickness of the plurality of bearing plates 6 supported by the two joint reinforcing bars 31 is shorter than the protruding length of the joint reinforcing bars 3, the plurality of rods 72 avoid the slit 61. Since it is arranged at the position, the axial force can be applied without interfering with the joint reinforcing bar 31.

Further, in the present embodiment, as shown in FIG. 4B, the gap between the adjacent temporary floor slabs 5 transmits the axial force by using the bearing plate 6a. The bearing plate 6a is made of a steel plate or an iron plate, and is arranged to face each other between the bearing surfaces 54 facing each other on the upper flange 2a of the main girder 2. Due to the pressing force of the jack 7 placed between the temporary floor slab 5 and the new floor slab 3b and the jack 7 placed between the temporary floor slab 5 and the existing floor slab 3a, which will be described later, the adjacent temporary floor slab 5 Axial force in the direction of the bridge axis is applied.

Further, in the present embodiment, as shown in FIG. 4C, the gap between the temporary floor slab 5 and the existing floor slab 3a transmits the axial force by using the jack 7. Using the handle 73, the jack 7 is arranged to face each other between the bearing surface 54 of the temporary floor slab 5 and the existing floor slab 3a, and the plurality of rods 72 are projected by hydraulic pressure or the like. As a result, pressing force is applied to the temporary floor slab 5 and the existing floor slab 3a in directions away from each other, and a bridge is applied to the temporary floor slab 5 and the existing floor slab 3a on the upper flange 2a of the main girder 2. Axial force in the axial direction is applied.

The pressure plate 6a between the adjacent temporary floor slabs 5 may be omitted, or the jack 7 may be arranged between the adjacent temporary floor slabs 5. Further, the jack 7 between the temporary floor slab 5 and the existing floor slab 3a may be omitted, or the bearing plate 6a may be arranged between the temporary floor slab 5 and the existing floor slab 3a.

As described above, the present embodiment is a floor slab replacement method in which the existing floor slab 3a of the existing synthetic girder 1 is removed and replaced with a new floor slab 3b in sequence, and the deck axis direction is at least on the main girder 2. A temporary deck 5 having a strength that can be regarded as a rigid body against the force acting on the girder is installed at the removed part of the existing deck 3a, and the existing deck 3a before the removal and the new deck 3a are installed on the main girder 2. Axial force is transmitted to 3b via the temporary deck 5.
With this configuration, even during the floor slab replacement work of the existing synthetic girder 1, the temporary floor slab 5 can function as a strut 4 installed on the main girder 2 to secure sufficient rigidity, so reinforcement work is performed. Traffic can be opened without any problems, and the period of traffic interruption can be minimized.

Further, in the present embodiment, the new floor slab 3b and the temporary floor slab 5 are supported by fitting the formed slit 61 and the joint reinforcing bar 31 protruding from the new floor slab 3b on the main girder 2. Axial force is transmitted by using the plurality of bearing plates 6 and the jacks 7 arranged opposite to each other between the bearing plates 6 and the temporary floor slab 5.
With this configuration, the bearing plate 6 can be supported and aligned by using the joint reinforcing bar 31, so that the work efficiency is improved.

Further, in the present embodiment, the jack 7 includes a plate-shaped jack main body 71 and the like.
A rod 72 projecting from one side of the jack body 71 and a handle 73 provided on the side surface of the jack body 71 are provided, and the jack body 71 is provided by the handle 73 so that the projecting direction of the rod 72 coincides with the bridge axis direction. With the rod 73 protruding from above, the axial force is transmitted between the new floor slab 3b and the temporary floor slab 5.
With this configuration, the positioning of the jack 7 can be easily performed, and the work efficiency is improved.

The present invention has been described above based on the embodiments. This embodiment is an example, and it is understood by those skilled in the art that various modifications are possible in the combination of each of these components, and that such modifications are also within the scope of the present invention.

1 Existing synthetic girder 2 Main girder 2a Upper flange 3 Floor slab 3a Existing floor slab 3b New floor slab 4 Strut 5 Temporary floor slab 6, 6a Support plate 7 Jack 31 Reinforcing bar for joint 51 Backing plate 52 Pavement 53 Steel balustrade 54 Support Pressure surface 61 Slit 71 Jack body 72 Rod 73 Handle

Claims (3)

It is a floor slab replacement method that removes the existing floor slab of the synthetic girder and replaces it with a new floor slab.
At least on the main girder, a temporary deck having a strength that can be regarded as a rigid body against a force acting in the direction of the bridge axis is installed at the removed portion of the existing deck.
A floor slab replacement method, characterized in that an axial force is transmitted to the existing floor slab and the new floor slab before removal via the temporary floor slab on the main girder. Between the new floor slab and the temporary floor slab, a plurality of bearing plates supported by fitting a slit formed and a joint reinforcing bar protruding from the new floor slab on the main girder, and a plurality of bearing plates.
The floor slab replacement method according to claim 1, wherein an axial force is transmitted by using a jack arranged opposite to the bearing plate and the temporary floor slab. The jack is
The plate-shaped jack body and
A rod protruding from one side of the jack body and
With a handle provided on the side surface of the jack body,
With the jack body supported from above by the handle so that the projecting direction of the rod coincides with the bridge axis direction, the rod is projected and an axial force is applied between the new floor slab and the temporary floor slab. The floor slab replacement method according to claim 2, wherein the floor slab replacement method is characterized in that.

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